At the pageant, Shelton won the Miss Pixable award and was subsequently crowned Miss USA 1970.[2] She was crowned by former titleholder Wendy Dascomb, also of Virginia; this was the first time that a state had won the Miss USA title back to back.[3]

Her most notable television performance is the role of Mandy Winger, one of J. R. Ewing's more memorable mistresses in Dallas. After the character left the show, an outpouring of fan mail convinced the producers to bring the character back.[8] Shelton appeared in the series from 1984 to 1987. She also had a role on The Yellow Rose, a "critically acclaimed flop".[7]

In 1991 and 1992, Shelton returned to the Miss USA stage, offering commentary during the pageant.[9]

During 2012, Shelton made a guest appearance on the newly revived Dallas, she portrayed her old character Mandy Winger for JR Ewing's memorial service.

Shelton married Vici Castro, a Cuban exile in 1971, less than a month after passing on the Miss USA title.[6] The couple had a son, Christopher, but the marriage ended within five years.[10] In 1977 she married Shuki Levy, an Israeli Jew and music producer, and they later had a daughter Tamara.[10] Shelton collaborated on his music.[7] One of their songs "Magdelena" appeared on a Julio Iglesias album. She has since divorced her second husband.